5,665,500,000 to
14,634,000,000 km
3,518,000,000 to
9,088,000,000 miles

2,326 km
(1,445 miles)

8 hours

557 years

-248 to -232 °C-414 to -386 °F

2005

1

Additional Information

DISTANCE FROM THE SUN:The distance from the Sun given in the above table is the average distance the planet is away from the
Sun. The planets don't orbit in completely circular orbits but in most cases, the difference between the planet's closest distance from the
Sun doesn't vary greatly from its furthest point. Where the orbits are more elliptical than circular (where the planet's closest distance from the
Sun varies greatly from its furthest point) the range is given.

DIAMETER:The diameters of Jupiter and
Saturn are wider across the equator (the values given in the table) than they are from their North to their South Poles. This is because of their fast rotational speeds which "squash" the planets.
Dwarf Planet Haumea has an elongated shape so its dimensions rather than average diameter is given.

TIME TO SPIN ON AXIS:This is the length of time it takes for the planet to complete one full rotation. This is measured in
Earth time. For example, in the case of
Mercury, it takes the planet 59 Earth days to spin on its axis.

TIME TO ORBIT SUN:This is the length of time it takes for the planet to complete one full journey around the
Sun. This is measured in Earth time. For example, in the case of
Mars, it takes the planet 687 Earth days to orbit the
Sun.

AVERAGE TEMPERATURE:The average temperatures for the rocky
Inner Planets (Mercury,
Venus, Earth and
Mars) and the Dwarf Planets (Ceres,
Pluto and Eris) are the temperatures at the surface. The average temperatures for the
Outer Planets (Jupiter,
Saturn, Uranus and
Neptune) are the temperatures at the tops of the planets' clouds. These gas planets will be hotter towards their - possibly solid - cores, generating their own heat sources, giving off more heat than they actually receive from the
Sun. Where there is a large difference between the maximum and the minimum temperature on a planet, the full temperature range is given.

CONTENTS OF ATMOSPHERE:Mercury is too small to
actually possess a "sky-like" atmosphere. The gases listed in the table for
Mercury are gases that surround the planets.

YEAR OF DISCOVERY:The planets Mercury to
Saturn were observed thousands of years ago and therefore don't have a date of discovery since there is nobody credited with being the first person to spot them.
Uranus was the first planet to be discovered. It may possibly have been seen before its official date of discovery, but it would not have been recognised as a planet.

KNOWN MOONS:Moons are constantly being discovered orbiting planets. The number of moons listed are the number confirmed when this page was updated (July
2015).